<html xmlns="http://www.w3.org/1999/xhtml" style="border-color: black">
  <head>
    <style>
      html { color: black; border-width: 10px; border-style: solid; }
    </style>
  </head>
  <body>
    <html style="border-color: green;">Test</html>
  </body>
</html>
